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2011 R1200RT Bike lurches at low throttle position

Anyone come across this problem before? I can't seem to roll the throttle smoothly without the bike lurching. I can't ride the bike smoothly at low speeds (engine at 2000 to 3000 rpm). When I slightly roll from the closed throttle position the engine and bike surges forward, it dosen't matter how slowly I roll the grip, it surges. It is really bad in 2nd gear, especially going around curves and in traffic, the bike is constantly hopping back and forth as I roll the grip. This always happens while in gear.

My 2012 does it in 1st and 2nd gear around the same RPM's that your your talking about. I can keep it from "lurching by finessing the clutch while at slow speeds in 1st. I typically carry enough speed when cornering in 2nd. When I do occasionally corner slower in 2nd it is annoying and unsettling.

What you've described is common for hexhead (and other) engines. At that low of an RPM the throttle is off or mostly off and any throttle change causes a large change in RPM. Once the bike got above about 3000 RPM all was well. On my GS I did three things to make it slightly better.

1) try not to lug the engine by keeping the RPM up if at all possible. At very low speeds I'd repeatedly accelerate and coast with the clutch in instead of trying to maintain a constant speed at too low of an RPM.

2) use two fingers on the brake. This has little to do with covering the brake and lots to do with giving myself better fine control of the throttle.

3) use something like the Accelerator module or the Boosterplug. That let me get a smooth, non-lurching ride down to about 2400-2500 RPM. Below that I used the technique described in 1) above.

My GS was not a camhead, so I can't say for sure that my experience is apropos for your bike.

This is how my 1150RT also seemed when I got it. A good tune and good technique will minimize the impact. On my 1150 I replaced the stock O2 sensor with one that adds about 6% to the fueling (Innovate Motorsports LC-1). That fully eliminated the condition. The LC-1 has been installed on a couple 1200s with similar results; however, the LC-1 is far from a plug & play solution, it takes wiring skill. Later this year, I expect there will be a plug 'n play version of an LC-1. for 1200s. I'm working with someone to build it now.
RB

My 06 RT has never done that. I can ride down to around 2500 rpm in first or second gear and with a gentle roll on the bike just smoothly accelerates to whatever speed I want. My 04 1150 Rt never did that either.

My '12 RT does not lurch either. How many miles (or in your case kilometers, I guess) are on your bike? Have the throttle bodies been synced?

Thank you all for your comments, but now I'm confused. Some say that everyone has this problem and some never had it. I can't believe that this bike, with ECU, fuel injected and a multitude of sensors, can't control the engine at the low end of the throttle position. There must be something wrong.

Today, I tried what some of you suggested and I just can't make it work smoothly. I don't lug the engine and today I kept the revs much higher and still it lurched. Driving in traffic is terrible, I just can't avoid this throttle position.

My bike only has 5000 km and maybe I should sync the throttle bodies, as you suggested.

Thank you all for your comments, but now I'm confused. Some say that everyone has this problem and some never had it. I can't believe that this bike, with ECU, fuel injected and a multitude of sensors, can't control the engine at the low end of the throttle position. There must be something wrong.

Today, I tried what some of you suggested and I just can't make it work smoothly. I don't lug the engine and today I kept the revs much higher and still it lurched. Driving in traffic is terrible, I just can't avoid this throttle position.

My bike only has 5000 km and maybe I should sync the throttle bodies, as you suggested.

Thanks again for your comments.

I think your going to have to finesse it with your clutch when making low speed tight turns or trying to idle or be at low RPM's. If you let the clutch out completely at lower RPM I don't think you'll avoid it. I can keep mine from doing it but it will lurch if I don't finesse the clutch. I went and tried the new 90th anniversary demo at the dealership it it performed the same way.

My 06 RT has never done that. I can ride down to around 2500 rpm in first or second gear and with a gentle roll on the bike just smoothly accelerates to whatever speed I want. My 04 1150 Rt never did that either.

Try it at 1800 RPM. Try to ride at a constant 10 MPH smoothly with out playing with the clutch.

I think your going to have to finesse it with your clutch when making low speed tight turns or trying to idle or be at low RPM's. If you let the clutch out completely at lower RPM I don't think you'll avoid it. I can keep mine from doing it but it will lurch if I don't finesse the clutch. I went and tried the new 90th anniversary demo at the dealership it it performed the same way.

By the way I have a 2012 with 3600 miles on it.

Abrupt throttle response, light-load surging, weaker torque in the 2000-3000 rpm range are all results of the lean fueling that BMW adopted to meet emission requirements back in the early 90s on the Oilheads. BMW did provide an example of how they wanted these bikes to perform?the European, non-cat maps for the R1100. They were only 5-6% richer but when properly setup, running non-ethanol fuel, they ran (still run) great.

This is a long shot, but you might re-adjust the clutch perch setting. Once I picked up by RT from the dealer, and the mechanic had set the perch setting to his liking - way too short. The bike did lurch then, but after I re-adjusted the lever, all was well.

If that bike acts like that, consider taking it back to the dealer and have the mechanic test drive it. You didn't buy an expensive BMW only to have it perform in a jerky fashion in traffic.

This is a long shot, but you might re-adjust the clutch perch setting. Once I picked up by RT from the dealer, and the mechanic had set the perch setting to his liking - way too short. The bike did lurch then, but after I re-adjusted the lever, all was well.

If that bike acts like that, consider taking it back to the dealer and have the mechanic test drive it. You didn't buy an expensive BMW only to have it perform in a jerky fashion in traffic.

Thank you all, I will try a few things and if nothing works I will bring it up at my 10k service.